O 系统变量

• OBJECTISOLATIONMODE
• OBSCUREDCOLOR
• OBSCUREDLTYPE
• OFFSETDIST
• OFFSETGAPTYPE
• OLEFRAME
• OLEQUALITY
• OLESTARTUP
• OPENFILTERINDEX
• OPENFORMATVERSION
• OPENGLTEXTURESIZEMAX
• OPMSTATE
• ORBITAUTOTARGET
• ORTHOMODE
• OSMODE
• OSNAPCOORD
• OSOPTIONS